RESUMO
This study is an effort to produce a generic and comprehensive solution to the simulation of mass diffusion through a multiphasic and heterogeneous material model. A Galerkin-type finite element formulation is developed to solve Fick's equation for steady-state and time-dependent analysis. The effect of the interface in modelling of a liquid-solid medium is presented in this work. To show the robustness of the proposed approach, the gas exchange (oxygen and carbon dioxide) process through the capillary network between the alveolar membrane and red blood cells has been analysed and then validated with experimental data. The current work is a significant asset to modelling the diffusion of oxygen between cells and scaffolds in tissue engineering or tissue regeneration/repair studies. It is one step towards the development of high-order elements for application of the simulation of mass transfer through a multiphasic and porous model with varying degrees of interconnectivity and pore size for tissue engineering applications.
Assuntos
Materiais Biocompatíveis/química , Teste de Materiais/métodos , Modelos Biológicos , Modelos Químicos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Animais , Transporte Biológico/fisiologia , Simulação por Computador , Desenho Assistido por Computador , Difusão , Desenho de Equipamento , Análise de Falha de Equipamento , Análise de Elementos Finitos , HumanosRESUMO
In this study, the antioxidant activity of methanol and aqueous extracts of Crataegus pentaegyna subsp. elburensis (CP) were examined by various in vitro assay systems, i.e., DPPH and nitric oxide radical scavenging, reducing power, linoleic acid and iron ion chelating power. IC50 for DPPH radical-scavenging activity was 341.29 +/- 1.29 for methanol and 269.31 +/- 2.11 microg mL(-1) for aqueous extract. Reducing powers of extracts also increased with the increase of their concentrations. Both extracts exhibited a weak reducing power at 25-800 microg mL(-1). Extracts exhibited weak nitric oxide radical scavenging and Fe2+ chelating ability. Methanol extract showed higher Fe2+ chelating ability (IC50 = 1.84 +/- 0.01 mg mL(-1)). Both tested extracts exhibited high antioxidant activity. Extracts showed high total phenolic content.
